Implantable devices in body tissue which operate at the Medical Implant Communications Service (MICS) frequency need to overcome the lossy medium created by body tissue.
Antennas operate most efficiently at a dimension which is a quarter of a wavelength of signals transmitted or received by the antenna. However, using the MICS frequency range the optimum quarter wavelength would result in an antenna having dimensions of approximately 0.2 m. An antenna of this length would be exceedingly difficult to implant into a patient without significant surgical invasion and discomfort to the patient.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.